Function func

src/click/_compat.py:589–606

()

    cache: cabc.MutableMapping[t.TextIO, t.TextIO] = WeakKeyDictionary()

    def func() -> t.TextIO | None:
        stream = src_func()

        if stream is None:
            return None

        try:
            rv = cache.get(stream)
        except Exception:
            rv = None
        if rv is not None:
            return rv
        rv = wrapper_func()
        try:
            cache[stream] = rv
        except Exception:
            pass
        return rv

    return func